Java超简明入门学习笔记（三）

 1 class StringTest{
 2     StringTest(){
 3         s3 = "4567";
 4     }
 5 
 6     String s1;
 7     String s2 = "1234";
 8     String s3;
 9 }
10 
11 public class MainTest {
12     public static void main(String[] args) {
13         StringTest st = new StringTest();
14         System.out.println(st.s1);
15         System.out.println(st.s2);
16         System.out.println(st.s3);
17     }
18 }

 1 class Test{
 2     Test(){
 3         System.out.println("Test");
 4     }
 5 
 6     Test(String s){
 7         System.out.println(s+"test");
 8     }
 9 }
10 
11 public class MainTest {
12     public static void main(String[] args) {
13         Test t = new Test();
14         Test t2 = new Test("1234");
15     }
16 }

 1 class Dog{
 2     Dog(int i){
 3         System.out.println("barking");
 4     }
 5 
 6     Dog(double d){
 7         System.out.println("howling");
 8     }
 9 
10     Dog(char c){
11         System.out.println("Meow~");
12     }
13 
14     Dog(int i, boolean b){
15         System.out.println("I B");
16     }
17 
18     Dog(boolean b, int i){
19         System.out.println("B I");
20     }
21 }
22 
23 public class MainTest {
24     public static void main(String[] args) {
25         Dog d1 = new Dog(1);
26         Dog d2 = new Dog(1.5);
27         Dog d3 = new Dog(‘c‘);
28 
29         Dog bi1 = new Dog(1,true);
30         Dog bi2 = new Dog(true,1);
31     }
32 }

 1 class Test{
 2     int i;
 3     double d;
 4 }
 5 
 6 public class MainTest {
 7     public static void main(String[] args) {
 8         Test t = new Test();
 9         System.out.println(t.i);
10         System.out.println(t.d);
11     }
12 }

 1 class Test{
 2     void method1(){
 3         method2();
 4         this.method2();
 5     }
 6 
 7     void method2(){ System.out.println("Ah,be called!!"); }
 8 }
 9 
10 public class MainTest {
11     public static void main(String[] args) {
12         Test t = new Test();
13         t.method1();
14     }
15 }

 1 class Test{
 2     Test(String s, double i){
 3         this(i);
 4         ss = s;
 5 
 6         System.out.println("name: "+ss);
 7         System.out.println("Area: "+ii);
 8     }
 9 
10     Test(double i){
11         ii = i*i*3.14;
12     }
13 
14     String ss;
15     double ii;
16 }
17 
18 public class MainTest {
19     public static void main(String[] args) {
20         Test t = new Test("Circle",2);
21     }
22 }

 1 class Test{
 2     protected void finalize(){
 3         //super.finalize();
 4         System.out.println("Ah!!NO!!!");
 5     }
 6 }
 7 
 8 public class MainTest {
 9     public static void main(String[] args) {
10         Test t = new Test();
11         System.gc();
12     }
13 }

 1 class Tank{
 2     protected void finalize(){
 3         //super.finalize();
 4         if(isFull){
 5             System.out.println("Not Good");
 6         }
 7         else{
 8             System.out.println("Good!");
 9         }
10     }
11 
12     boolean isFull = false;
13 }
14 
15 public class MainTest {
16     public static void main(String[] args) {
17         Tank t = new Tank();
18         System.gc();
19     }
20 }

 1 class Test{
 2     static String s1 = "1234";
 3     static String s2;
 4     static{
 5         s2 = "4567";
 6     }
 7 
 8     static void func(){
 9         System.out.println(Test.s1);
10         System.out.println(Test.s2);
11     }
12 }
13 
14 public class MainTest {
15     public static void main(String[] args) {
16         Test.func();
17     }
18 }

1 class Test{
2     String s1;
3     {
4         s1 = new String("1234");
5     }
6 }

1 public class MainTest {
2     public static void main(String[] args) {
3         String[] arrayString = {"1111","2222","3333","4444"};
4         for(String s:arrayString)
5         {
6             System.out.println(s);
7         }
8     }
9 }

 1 class Test{
 2     Test(String s){
 3         System.out.println(s);
 4     }
 5 }
 6 
 7 public class MainTest {
 8     public static void main(String[] args) {
 9         Test[] arrayTest = new Test[]{
10                 new Test("123"),
11                 new Test("456")
12         };
13     }
14 }

 1 class Test{
 2     Test(String... s){
 3     }
 4 }
 5 
 6 public class MainTest {
 7     public static void main(String[] args) {
 8         Test t1 = new Test("111","222");
 9         Test t2 = new Test(new String[]{"333","444"});
10     }
11 }

1 public class MainTest {
2     public static void main(String... args) {
3         for(String s:args)
4         {
5             System.out.println(s);
6         }
7     }
8 }

 1 enum CNY{
 2     CNY1,CNY5,CNY10,CNY20,CNY50,CNY100;
 3 }
 4 
 5 public class MainTest {
 6     public static void main(String[] args) {
 7         for (CNY temp : CNY.values()) {
 8             System.out.println(temp + " " + temp.ordinal());
 9         }
10 
11         CNY cnyTemp = CNY.CNY5;
12         switch (cnyTemp){
13             case CNY1:
14                 System.out.println("1 Yuan");
15                 break;
16 
17             case CNY5:
18                 System.out.println("5 Yuan");
19                 break;
20 
21             case CNY10:
22                 System.out.println("10 Yuan");
23                 break;
24 
25             case CNY20:
26                 System.out.println("20 Yuan");
27                 break;
28 
29             case CNY50:
30                 System.out.println("50 Yuan");
31                 break;
32 
33             case CNY100:
34                 System.out.println("100 Yuan");
35                 break;
36 
37             default:
38                 System.out.println("Error : Fake Money");
39         }
40     }
41 }